The objective of the project is to develop the final stage of User Interface software helpful for hyperthermia system operator to access patient files easily. The user interface is developed in Matlab. Earlier for a system operator to view each patient’s CT scan image files, it was required to select each file individually; thus, it was difficult to observe and study multiple images of the same patient at same time.
In this project, the effort aims to successfully complete and test the user interface, which enables the hyperthermia system operator to access the patient files from any folder and transfer these files to the executable MATLAB © program to display. Once the files are transferred, the program gives the operator flexibility to adjust the treatment antenna position to maximize heating on the tumor area, with minimum effect on the surrounding healthy tissue.
Simulation studies were performed on actual veterinary patient data that was obtained as a collaborative effort with the University of California, Davis, School of Veterinary Medicine. These simulations in Matlab involved accessing the patient CT scan files directly into the main Matlab Treatment Planning program, and then illustrating the electric field and temperature distributions over the treatment volume. One important aspect of the simulation that was developed in this project work was the mouse control of the antenna position, with the aim of focusing the heating on the tumor volume.
BACKGROUND ON VETERINARY HYPERTHERMIA
RF or Microwave Hyperthermia is used for both human and veterinary patients as an adjuvant therapy in cancer treatment. However, modalities and applicators would vary in both types of patients, on account of differences in body and tissue structure.
Early Work on Veterinary Hyperthermia Application:
Hyperthermia is old therapy for cancer. A lot of research has been already done on it. While doing a study of this topic we went through some research work which is mentioned in this chapter. Some of the first hyperthermia work in veterinary cancer applications was initiated by Gillette Chryanthopoulos et al, Grier et al and Brewer et al. Gillette’s study showed that hyperthermia removed the complete tumor but at a different rate of reduction for tumor cells. A mathematical model for thermal interactions between normal and neoplastic tissues is in mammalian species developed by Chryanthopoulos et al.
Recent and Current Work in Veterinary Hyperthermia Application:
After studying these case studies, we realized that this is a therapy which has a lot of aspects. One key aspect of the hyperthermia treatment planning system is the position of the antenna. The aim of this software module is to use patient’s data (which are ct scan files) as an input and using temperature and electric field distribution algorithms it plots a graph of these parameters and this software module works in iteration mode, so hyperthermia system operator has the feasibility to adjust antenna position.
DESIGN OF HYPERTHERMIA TREATMENT PLANNING SOFTWARE
The software is developed and tested by using actual animal patient imaging data that was obtained from UC Davis School of Veterinary Medicine (veterinary cancer patient CT scan data). The data is in the form of DICOM (Digital Imaging and Communications in Medicine) format.
SIMULATION RESULTS BASED ON VETERINARY PATIENT DATA
In this chapter, the simulation results obtained for another subfolder SE000003 of the patient nikkita are described. The output figure window for CT scan images, temperature distribution and electric field distribution are shown.
CONCLUSIONS AND FUTURE WORK
Thus, we have developed a code with which hyperthermia operator can easily select a folder of the patient as easily as we can select any folder on the computer to display a collage of CT scan images. The tumor area is precisely selected by using mouse. So, antenna radiation can be coherently focused on malignant cells. Similarly, the code displays the second set of results which contains temperature distribution of tumor cells and the third result displays electric field distribution.
The temperature distribution displays temperature of cells helping to keep temperature in range of 42°C – 45°C. On the electric field distribution, the system operator can select x and y coordinate of antenna position for next iteration, using a mouse. On selection of x and y coordinates on electric field distribution, updated values for temperature distribution and electric field distribution plot are displayed. These iterations can be continued until the desired position of the antenna for generating heat is obtained.
In the second part of the project, work will be continued to analyze what are header files in a folder and how to extract pixel spacing information of images directly from the DICOM files. This will make the code more user-friendly for the operator, as compared to the manual entering of pixel spacing information in the code. Future work will also involve actual feedback of optimal antenna position to the UC Davis Veterinary Science staff, and enable them to add hyperthermia as an adjuvant therapy for the patient under study.
Source: California State University
Authors: Jayesh Gharat | Gaurav Kakade